The basic structure of a WIMAX (Worldwide Interoperability for Microwave Access) network is shown in FIG. 1, in which each logical entity represents a group of functional entities, and each function can be implemented in a single physical device or a plurality of distributed physical devices.
An ASN (Access Service Network) belongs to an NAP (Network Access provider) and comprises:
an FA (Foreign Agent), which is a mobile IP;
a BS (Base Station), which is situated within the ASN;
an AGW (ASN Gateway), which is an edge device between the ASN and a CSN (Connectivity Service Network);
a PC (Paging Controller), which is in charge of initiating paging or controlling an MS (Mobile Station) entering IDLE;
an LR (Location Register), which is in charge of storing information about an IDLE MS;
a DPF (Data Path Function), which is in charge of managing establishment, maintenance and deletion of a service flow path; and
an SFA (Service Flow Authorization), which is in charge of initiating a resource reservation request and maintaining a service flow's parameters such as QoS (Quality of Service), classifier and so on.
An H-NSP (Home Network Service Provider) is in charge of authentication of an MS, authorization of a service, and management of IP host configuration, etc. The authentication function is performed between an MS and a CSN of the H-NSP. In a roaming mode, an ASN and a CSN of a V-NSP (Visit Network Service Provider) may also process part of the authentication flow and mechanism.
An AAA (Authentication/Authorization/Accounting) server is situated in the H-NSP or a CSN of the V-NSP.
In a Wimax network, a plurality of service flows can be established between an MS terminal and each ASN, and each of the service flows can have a different QoS, direction, classifier, and so on. The service carried on each of the service flows may also be different, for example, a user generates an uplink service flow (SFID (Service Flow Identification)=1) and two downlink service flows (SFID=2 and SFID=3), wherein the uplink service flow can be used for an FTP (File Transfer Protocol) request, a streaming media request, etc., and the downlink service flow can be used to carry content of a download file and information of a streaming media.
In a Wimax network, an MS can enter IDLE state, in which case the BS will not store any information about the MS, but only the AGW has information of all the service flows of the MS. Moreover, when an MS is in IDLE state, downlink data can induce paging of the MS by the AGW.
The current paging mechanism has some defects because downlink service flows of each MS may also include a downlink initial service flow without a classifier in addition to service flows with definite service types. When a user of an exterior network scans a network segment of users in an ASN, for example, a special message is constructed and sent to all the IP addresses in the network segment of the users, and an HA (Home Agent) will forward these downlink data to the AGW; if many MSs in the access network are in IDLE state, for each MS in IDLE state, if the MS has a downlink service flow of the same type as the received downlink data, the PC will initiate paging of the MS; if the MS does not have a downlink service flow of the same type as the received downlink data, the AGW will consider by default that the MS has an downlink initial service flow that can be used for the message to initiate paging, so the PC will also initiate paging of the MS, and as such, the PC will initiate paging of all the MSs in IDLE state. As a result, the AGW, BS and MSs all need to initiate a series of unnecessary paging flows, which is a serious waste of resources for the operator.